Short Wavelength Visible Light-Emitting Toothbrush With An Electronic Signal Interlock Control

Abstract

A toothbrush having one or more light sources with an electronic interlock control device preventing operation of the light source when the toothbrush is removed from the user's mouth. The electronic interlock control over operation is necessary to prevent accidental eye exposure to the high intensity light source with a wavelength in the range of about 400 nm to about 1000 nm. The light-emitting toothbrush activates upon entering the user's mouth but deactivates immediately when removed, thus protecting the user's eyes from direct exposure to the high power light source contained in the brush head.

What is claimed is: 
     
         1 . A toothbrush having a light source comprising:
 a battery, a light assembly, electronics coupled to the battery and the light assembly, the brush including a handle and a distal end with bristles mounted on the distal end;   the light assembly comprising a light source with a within the handle which directs a light beam through a light pipe made from a non-conductive plastic installed in the distal end and emitting light out of an aperture;   the distal end including bristles mounted on the distal end and a light aperture, the distal end being equipped with a first electrical contact accessible on an exterior surface and a second electrical contact accessible on an exterior surface, the first and the second electrical contacts being the separated from one another by a non-conductive region of one of the handle or distal end to create an open circuit;   the first and second electrical contact connected to the electronics, said electronics being adapted to determine whenever the distal end is outside the environment of the mouth, and permit activation of the source of light only when the source of light is inside the mouth of the user and a current signal loop is completed through the first and second electrical contacts and the body of the user.   
     
     
         2 . The toothbrush as claimed in  claim 1 , wherein the light pipe is comprised of a non-conductive plastic and is encased in a conductive plastic which is electrically connected to the first electrical contact in the distal end. 
     
     
         3 . The toothbrush as claimed in  claim 1 , wherein the light pipe is comprised of a non-conductive plastic and encased in a non-conductive plastic which contains a wire connected to the control electronics in the handle and the first electrical contact in the distal end. 
     
     
         4 . The toothbrush as claimed in  claim 3 , wherein the wire is the first electrical contact. 
     
     
         5 . The toothbrush as claimed in  claim 1 , wherein the light assembly includes an LED light source and a parabolic light source concentrator to focus the light beam into the light pipe. 
     
     
         6 . The toothbrush as claimed in  claim 5 , wherein the parabolic concentrator emits light at an angle of incidence to create total internal reflection within the light pipe enabling the light beam to travel along the light pipe. 
     
     
         7 . The toothbrush as claimed in  claim 5 , wherein the light pipe and light source concentrator are less than about 8 mm in diameter. 
     
     
         8 . The toothbrush as claimed in  claim 1 , wherein the light source is a laser diode. 
     
     
         9 . The toothbrush as claimed in  claim 1 , wherein the light source emits at a wavelength in the range of 400 nm to 500 nm. 
     
     
         10 . The toothbrush as claimed in  claim 1  further including a beam-steering component to direct emitted light from the light source concentrator to the light aperture. 
     
     
         11 . The toothbrush as claimed in  claim 10 , wherein the beam-steering component is a lens. 
     
     
         12 . The toothbrush as claimed in  claim 1 , wherein the light pipe comprises a curved surface to guide the emitted light to the aperture. 
     
     
         13 . The toothbrush as claimed in  claim 1 , wherein the distal end mounts on the handle with a bayonet mount. 
     
     
         14 . The toothbrush as claimed in  claim 1 , wherein the distal end mounts on the handle with a press fit. 
     
     
         15 . The toothbrush as claimed in  claim 1 , wherein the handle has a female fitting light source concentrator and the distal end mounts on the handle by insertion in the female fitting. 
     
     
         16 . The toothbrush as claimed in  claim 1 , wherein the handle has a male fitting light source concentrator and the distal end mounts on the handle by insertion of the handle into a female fitting on the distal end. 
     
     
         17 . The toothbrush as claimed in  claim 1  further including an alarm adapted to warn the user of the power status of the source of light before it reaches full power. 
     
     
         18 . The toothbrush as claimed in  claim 17 , wherein the alarm is a ramp-up sequence comprising a short burst of low frequency light pulses or flashes of the therapeutic light for a period of at least 0.5 seconds. 
     
     
         19 . The toothbrush as claimed in  claim 17 , where the alarm is a ramp-up sequence comprising a gradually increasing intensity of the therapeutic light over a period of at least 0.5 seconds. 
     
     
         20 . The toothbrush as claimed in  claim 17 , wherein the alarm is a vibrator coupled with a light emitter to warn the user of the power status of the source of light. 
     
     
         21 . The toothbrush as claimed in  claim 17 , wherein the alarm is an auditory device emitting a sound to warn the user of the power status of the source of light. 
     
     
         22 . The toothbrush as claimed in  claim 1 , wherein the light assembly further includes a secondary emitter with a wavelength in the range of 600 nm to 1000 nm. 
     
     
         23 . The toothbrush as claimed in  claim 22 , wherein the secondary light source is a vertical-cavity surface-emitting laser (VCSEL).